KR100617412B1 - Condensation Cross-Linking Polyurethane Materials Containing Special Aminosilanes, a Method for the Production Thereof and Their Use - Google Patents

Abstract

This invention relates to polyurethane compositions which cross-link via a silane polycondensation and contain at least one alkoxysilane-functional polyurethane, at least one basic filler, at least one reaction product of an aminosilane with a maleic or fumaric ester, at least one organometallic compound and optionally additional auxiliary substances, to a process for their preparation, and to their use.

Description

Condensation Cross-Linking Polyurethane Materials Containing Special Aminosilanes, a Method for the Production Thereof and Their Use}             

The present invention contains at least one alkoxysilane functional polyurethane, at least one basic filler, at least one reaction product of aminosilane with maleic ester or fumaric acid ester, at least one organometallic compound and optionally additional auxiliary materials. A polyurethane composition crosslinked via silane polycondensation, a process for its preparation, and a use thereof.

Alkoxysilane functional polyurethanes crosslinked via silane polycondensation are a long known technique. An overview of this can be found in " Adhesives Age " 4/1995, p. 30 or less (author: Ta-Min Feng, B. A. Waldmann). These alkoxysilane terminated moisture cure monocomponent polyurethanes are increasingly being used as flexible elastic coatings, sutures and adhesive compositions in the construction and automotive industries. For this application, extensibility, adhesion and curing rate are highly required.

Such products are described, for example, in EP-A 596360, 831108, 807649 or 676403. Organometallic catalysts as well as aminosilane type adhesion promoters are generally used incidentally to form this type of system. However, the addition of aminosilane compounds can often lead to problems with storage stability, especially when high proportions of aminosilane are used to achieve good adhesion to materials that are difficult to adhere.

It is therefore an object of the present invention to provide a polyurethane composition crosslinked via silane polycondensation containing aminosilane and with improved storage stability.

This object is achieved by providing a polyurethane composition crosslinked by condensation described in the following detailed description.

The present invention

A) at least one alkoxysilane functional polyurethane having a terminal group of the formula (I)

B) at least one basic filler,

C) at least one reaction product of at least one aminosilane of formula II with at least one maleic ester or fumaric ester of formula III,

E) at least one organometallic compound, and

F) to provide a polyurethane composition crosslinked via silane polycondensation, containing optional further auxiliaries.

R ₃ OOC-CH = CH-COOR ₃

In the above formula, R ¹ is an organic group having 1 to 12 carbon atoms, R ² is a hydrogen atom or an aminoethyl group, R ₃ is an alkyl group having 1 to 12 carbon atoms, n is an integer of 2 to 4, X , Y, Z are the same or different organic groups, wherein at least one group is an alkoxy group having 1 to 4 carbon atoms, preferably a methoxy or ethoxy group.

The present invention is based on the surprising finding that the adducts of aminosilanes with maleic esters or fumaric acid esters according to the invention improve the mechanical properties and storage stability when used in place of the aminosilanes commonly used as adhesion promoters.

The reaction products of aminosilanes and maleic or fumaric acid esters which are used as component C) according to the invention are generally known and are described, for example, in EP-A 596360 or 831108. According to the disclosure of this patent, the reaction product of maleic ester or fumaric acid ester with aminosilane is used for the reaction of isocyanate prepolymers. The use of such products as adhesives to improve the mechanical properties and adhesion of polyurethanes crosslinked via silane polycondensation is not known until now.

Polyurethanes having alkoxysilane end groups used as component A) according to the invention are generally known and are prepared by the reaction of long chain, preferably linear NCO prepolymers with aminofunctional silanes of the formula (2).

Wherein R ¹ is an organic group having 1 to 12 carbon atoms, preferably a phenyl group, particularly preferably a group of formula (IIb), n is an integer of 2 to 4, preferably 3.

In the above formula, R ₄ is an alkyl group having 1 to 4 carbon atoms.

In the above formula, X, Y, Z are the same or different organic groups, wherein at least one group is an alkoxy group having 1 to 4 carbon atoms. Preferably, at least one group is a methoxy group or an ethoxy group. Especially preferably, all of X, Y and Z are methoxy groups.

Examples of suitable aminofunctional silanes of formula I are N-methyl-3-aminopropyltrimethoxysilane, N-methyl-3-aminopropyltriethoxysilane, N-butyl-3-aminopropyltrimethoxysilane . Preference is given to using N-phenyl-3-aminopropyltrimethoxysilane. Particular preference is given to using aspartic acid esters as described in EP-A 596360, which is formed through the reaction of an aminosilane of formula II with a maleic ester or fumaric acid ester of formula III.

NCO prepolymers that can be used to prepare polyurethanes A) with alkoxysilane end groups are prepared in a manner known per se by reacting polyether polyols, preferably polyether diols with diisocyanates, with an NCO content of 0.4 To 4%.

Compounds that can be used as basic filler B) are precipitated or ground chalk, metal oxides, metal sulfates, metal silicates, metal hydroxides, metal carbonates and metal bicarbonates. Other fillers are for example reinforced and unreinforced fillers such as exothermic or precipitated silica, carbon black or quartz powder. Both basic fillers and other reinforced or non-reinforced fillers may optionally be surface modified. Precipitated or ground chalk and pyrogenic silica are particularly preferably used as basic filler B). Of course, component B) can also be a mixture of fillers.

The compound used as component C) is the reaction product of an aminosilane compound of formula II with a maleic ester or fumaric acid ester of formula III.             

<Formula II>

<Formula III>

R ₃ OOC-CH = CH-COOR ₃

Wherein R ² , X, Y, Z and n are as defined above and R ₃ is an alkyl group having 1 to 12 carbon atoms.

Examples of useful aminosilane compounds of formula II include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-aminoethyl-3-aminopropyltrimethoxysilane, N-aminomethyl-3-amino Propyltriethoxysilane, 3-aminopropylmethyldiethoxysilane and N-aminoethyl-3-aminopropylmethyldimethoxysilane.

In formula (III), R ₃ is a linear or branched aliphatic hydrocarbon group having up to 12 carbon atoms. Examples of suitable maleic esters and fumaric acid esters are diethyl maleate, dimethyl maleate, dibutyl maleate, dioctyl maleate, diethyl fumarate, dimethyl fumarate, dioctyl fumarate.

When a product in which R ₂ is a hydrogen atom in formula (II) is used as aminosilane, aspartic acid ester of formula (IV) is formed during the reaction with maleic ester or fumaric ester according to the disclosure of EP-A 596360. .

Wherein R ³ , X, Y, Z and n are the meanings given in Formulas II and III above.

In certain preferred cases, when using a product wherein R ₂ is an aminoethyl group as the aminosilane of formula II, the piperazinone derivative of the formula V is formed via a cyclocondensation reaction.

Wherein R ₃ , X, Y, Z and n are the meanings given in Formula IV above.

All organometallic catalysts generally known to promote silane polycondensation can be used as component E). These are especially compounds of tin and titanium. Preferred tin compounds are, for example, dibutyltin dilaurate, dibutyltin diacetate and dioctyltin maleate, tin (II) octoate or dibutyltin bis (acetoacetonate). Preferred titanium compounds are, for example, chelated titanium compounds such as tetraisopropyl titanate, alkyl titanates such as tetrabutyl titanate, and ethyl diisobutylbis (acetoacetate) titanate. Dibutyltin bis (acetoacetonate) is particularly preferably used as component E).

Additives and auxiliaries F) according to the invention which may be mentioned are adhesives, thixotropic agents, light stabilizers, pigments and protective agents, for example fungicides, except as mentioned for desiccants, plasticizers, C).

Drying agents which may be mentioned specifically are alkoxysilyl compounds such as vinyltrimethoxysilane, methyltrimethoxysilane, i-butyltrimethoxysilane, hexadecyltrimethoxysilane. Examples of plasticizers that may be mentioned are phthalic acid esters, adipic acid esters, alkylsulphonic acid esters or phosphate esters of phenols. Examples of thixotropic agents that may be mentioned are polyamides, hydrogenated products of castor oil or also polyvinyl chloride. Known types of aminosilanes, epoxysilanes and / or mercaptosilanes can be used as adhesion promoters in addition to the compounds mentioned for C).

The polyurethane composition according to the invention preferably comprises component A) 30 to 80% by weight, component B) 10 to 50% by weight, component C) 0.5 to 3% by weight, component E) 0.02 to 1% by weight and component F) 0 to 40 weight percent.

The invention also provides a process for the preparation of the polyurethane composition according to the invention which is crosslinked by condensation. In the process according to the invention, component C) is prepared in a separate reaction vessel by reacting aminosilanes with maleic esters or fumaric esters in the temperature range of 0 ° C. to 100 ° C., similar to the disclosure of EP-A 596360 . Components A), B), E) and any F) are mixed together in the absence of water and then component C) is added thereto.

In a preferred embodiment of the process according to the invention, component C) used according to the invention is prepared in situ. In this procedure, components A), B), E) and optionally F) together with the maleic or fumaric acid esters used to prepare component C) are mixed together in the absence of water and then component C) The aminosilanes used according to the invention for the preparation of are added thereto.

The invention also provides the use of the reaction products of aminosilanes with maleic esters and fumaric acid esters which can be used according to the invention as component C) as additives in the polyurethane compositions crosslinked by condensation.

The invention also provides the use of the polyurethane composition according to the invention crosslinked by condensation, as a suture, an adhesive or a coating.

The polyurethane compositions according to the invention crosslinked by condensation cure rapidly with a skin formation time of 15 to 120 minutes, while exhibiting good storage stability in the temperature range below 60 ° C.

Crosslinked polymers exhibit improved mechanical properties, especially improved elongation at break, as compared to similar systems containing conventional aminosilanes. In addition, the polyurethane compositions according to the invention are characterized by good adhesion to all possible materials, in particular wet adhesion, for example metals, ceramics, plastics, stones or concrete.

Preparation of Polyurethane A1) with Alkoxysilyl End Groups

2000 g of polyether diol having a OH number of 28 (PO / EO ratio = 80:20) prepared by propoxylating propylene glycol and then ethoxylating the propoxylated product was 155.4 g of isophorone diisocyanate and dibutyltin at 70 ° C. 0.02 g of dilaurate was added to prepolymerize until the theoretical NCO content was 0.78%. After cooling the reaction mixture to 60 ° C., 140.4 g of N- (3-trimethoxysilylpropyl) aspartic acid diethyl ester (prepared according to European Patent EP-A 596360 Example 5) were added rapidly, The mixture was stirred until the isocyanate band no longer appeared in the IR spectrum. The viscosity of the resulting polyurethane prepolymer with alkoxysilyl end groups was 76000 mPas (23 ° C.).

Preparation of Polyurethane A2) with Alkoxysilyl End Groups

2000 g of polyether diol having a OH number of 28 (PO / EO ratio = 80:20) prepared by propoxylating propylene glycol and then ethoxylating the propoxylated product was 155.4 g of isophorone diisocyanate and dibutyltin at 70 ° C. 0.02 g of dilaurate was added to prepolymerize until the theoretical NCO content was 0.78%. After the reaction mixture was cooled to 60 ° C., 102 g of N-phenyl-3-aminopropyltrimethoxysilane were added rapidly and the mixture was stirred until the isocyanate band no longer appeared in the IR spectrum. The viscosity of the resulting polyurethane prepolymer with alkoxysilyl end groups was 86000 mPas (23 ° C.).

<Example 1>

Preparation of Polyurethane Compositions According to the Invention

In a commercial planetary mixer, the following components were processed to prepare a ready-to-use sealant.

Polyurethane A1) 36.4 parts by weight

Diisoundyl phthalate (plasticizer) 12.9 parts by weight

0.02 part by weight of dibutyltin bis (acetoacetonate) (10% solution in solvent naphtha 100)

1.50 parts by weight of vinyltrimethoxysilane

Sedimentation chalk (Type: Socal® U1S2) 46.2 parts by weight

2.00 parts by weight of diethyl melate

Disparlon (registered trademark) NVG8403 S (Keumoto Chem. Ltd. thixotropic agent) 1.40 parts by weight

The mixture was dispersed for 10 minutes at a pressure of 100 mbar, during which the internal temperature was raised to 60 ° C. Then 1.5 parts by weight of N-aminoethyl-3-aminopropyltrimethoxysilane were added and stirred for 10 minutes at a pressure of 100 mbar. The sutures thus prepared were excellent in stability, bound to virtually all materials and cured with a skin forming time of 30 minutes.

The product was charged to a commercial cartridge and stored at 50 ° C. After storage for 90 days, the product could still be processed without difficulty and its properties did not change.

Mechanical properties were measured as follows.

Tensile Strength 2.6 N / mm ² (DIN 53504)

Elongation at Break 268% (DIN 53504)

Tear Progression Resistance 5.4 N / mm (DIN 53515)

Shore A Hardness 42

<Example 2>

Preparation of Polyurethane Compositions According to the Invention

In a commercial oil peristaltic mixer, the following ingredients were processed to prepare ready-to-use sutures.

Polyurethane A2) 36.0 parts by weight

Diisoundyl phthalate (plasticizer) 12.6 parts by weight

0.02 part by weight of dibutyltin bis (acetoacetonate) (10% solution in solvent naphtha 100)

2.20 parts by weight of vinyltrimethoxysilane

Sedimentation chalk (Type: Solv (registered trademark) U1S2 by Solvay GmbH) 45.68 parts by weight

2.00 parts by weight of dimethyl melate                 

1.40 parts by weight of Cabosil® TS 720 (Exothermic Silica from Cabot GmbH)

The mixture was dispersed for 10 minutes at a pressure of 100 mbar, during which the internal temperature was raised to 60 ° C. Then 2.1 parts by weight of N-aminoethyl-3-aminopropyltrimethoxysilane were added and stirred for 10 minutes at a pressure of 100 mbar.

The sutures thus prepared were excellent in stability, bound to virtually all materials and cured with a skin forming time of 40 minutes.

The product was charged to a commercial cartridge and stored at 50 ° C. After storage for 90 days, the product could still be processed without difficulty and its properties did not change.

Mechanical properties were measured as follows.

Tensile Strength 2.8 N / mm ² (DIN 53504)

Elongation at Break 290% (DIN 53504)

Tear Progression Resistance 7.5 N / mm (DIN 53515)

Shore A Hardness 46

<Example 3>

Comparative example not in accordance with the present invention

Example 1 was difficultly repeated without adding diethyl maleic acid. The product was charged to a commercial cartridge and stored at 50 ° C. After storage for 60 days, the product was no longer extruded from the cartridge and gelled.

Mechanical properties were measured as follows.

Tensile Strength 2.5 N / mm ² (DIN 53504)

Elongation at break 235% (DIN 53504)

Tear Progression Resistance 5.6 N / mm (DIN 53515)

Shore A Hardness 42

<Example 4>

Comparative example not in accordance with the present invention

Example 2 was difficultly repeated without adding dimethyl maleic acid. The product was charged to a commercial cartridge and stored at 50 ° C. After 35 days of storage, the product was no longer extruded from the cartridge and gelled.

Mechanical properties were measured as follows.

Tensile Strength 2.8 N / mm ² (DIN 53504)

250% elongation at break (DIN 53504)

Tear Progression Resistance 7.4 N / mm (DIN 53515)

Shore A Hardness 46

Example 5

Preparation of Polyurethane Compositions According to the Invention

In a commercial oil peristaltic mixer, the following components were processed to produce ready-to-use sutures.

Polyurethane A1) 36.4 parts by weight

Diisoundyl phthalate (plasticizer) 12.9 parts by weight

0.04 part by weight of dibutyltin bis (acetoacetonate) (10% solution in solvent naphtha 100)

1.50 parts by weight of vinyltrimethoxysilane

Sedimentation chalk (Type: Socul (R) U1S2) 46.2 parts by weight

Disparon (registered trademark) NVG8403 S (Chetomorph, Thixotropic Agent) 1.40 parts by weight

The mixture was dispersed for 10 minutes at a pressure of 100 mbar, during which the internal temperature was raised to 60 ° C. Then 2.5 parts by weight of N- (3-trimethoxysilylpropyl) aspartic acid diethyl ester (prepared according to European Patent EP-A 596360 Example 5) were added and stirred at a pressure of 100 mbar for 10 minutes. Treated.

The sutures thus prepared were excellent in stability, bound to virtually all materials and cured with a skin formation time of 50 minutes.

The product was charged to a commercial cartridge and stored at 50 ° C. After storage for 90 days, the product could still be processed without difficulty and its properties did not change.

Mechanical properties were measured as follows.                 

Tensile Strength 2.5 N / mm ² (DIN 53504)

Elongation at Break 310% (DIN 53504)

Tear Progression Resistance 6.1 N / mm (DIN 53515)

Shore A Hardness 39

Claims (6)

A) at least one alkoxysilane functional polyurethane having a terminal group of the formula (I) B) at least one basic filler, C) at least one reaction product of at least one aminosilane of formula II with at least one maleic ester or fumaric ester of formula III, E) at least one organometallic compound and F) Polyurethane composition crosslinked via silane polycondensation, containing optional additional aids. <Formula I>

<Formula II>

<Formula III> R ₃ OOC-CH = CH-COOR ₃ Wherein R ¹ is an organic group having 1 to 12 carbon atoms, R ² is a hydrogen atom or an aminoethyl group, R ₃ is an alkyl group having 1 to 12 carbon atoms, n is an integer of 2 to 4, X, Y, Z are the same or different organic groups, wherein at least one group is an alkoxy group having 1 to 4 carbon atoms, preferably a methoxy group or an ethoxy group. The polyurethane composition crosslinked via silane polycondensation according to claim 1, wherein at least one alkoxysilyl functional polyurethane of the formula (I) is used as component A). <Formula I>

Wherein X, Y and Z are all methoxy groups. The polyurethane composition crosslinked via silane polycondensation according to claim 1 or 2, characterized in that at least one alkoxysilyl functional polyurethane of formula (I) is used as component A). <Formula I>

Wherein R ¹ is a group of formula IIb. <Formula IIb>

In the above formula, R ₄ is an alkyl group having 1 to 4 carbon atoms. The polyurethane composition crosslinked via silane polycondensation according to claim 1, wherein an aminosilane compound of formula V is used as component C). <Formula V>

Wherein R ₃ is a linear or branched aliphatic hydrocarbon group having 12 or less carbon atoms, n is 3, and X, Y, Z are methoxy or ethoxy groups. A) at least one alkoxysilane functional polyurethane having a terminal group of the formula (I) B) at least one basic filler, E) at least one organometallic compound, and F) optional additional aids are mixed together with the exclusion of moisture, C) A process for producing a crosslinked polyurethane composition by silane polycondensation, wherein at least one reaction product of at least one aminosilane of formula II and at least one maleic or fumaric acid ester of formula III is added thereto. . <Formula I>

<Formula II>

<Formula III> R ₃ OOC-CH = CH-COOR ₃ In the above formula, R ¹ is an organic group having 1 to 12 carbon atoms, R ² is a hydrogen atom or an aminoethyl group, R ₃ is an alkyl group having 1 to 12 carbon atoms, n is an integer of 2 to 4, X , Y, Z are the same or different organic groups, wherein at least one group is an alkoxy group having 1 to 4 carbon atoms, preferably a methoxy group or an ethoxy group. The polyurethane composition crosslinked via silane polycondensation according to claim 1, characterized in that it is used as a suture, adhesive or coating.